So Far, A Great Start For Corn, But Just An Average Weather Year

For much of Wisconsin, the 2010 corn crop got off to a great start. Crop progress
in some areas is at record pace for development. The crop is ahead of schedule because
of early planting dates, rather than significantly different weather. For many farmers
the crop is so tall that they are at lay-by in many of their fields. Dr. Bill Tracy
indicated that sweet corn inbreds planted May 18 are ready to be shoot bagged -
a record early date for him and his crew.

Figure 1 shows the weather data for UW-Agricultural Research Station at Arlington.
Precipitation is tracking at a pace similar to the 30-yr normal. Growing degree
unit (GDU) accumulation since January 1 is ahead of the 30-yr normal. But, while
total GDU accumulation is ahead of schedule, the GDU accumulation for various planting
dates is equivalent to the 30-yr normal for every planting date. For a May 1 planting
date, GDU accumulation was slower than the 30-yr normal while the crop was emerging,
but accumulation has since caught up. Uneven emergence was noted for this planting
date in a study at Arlington.

Figure 1. Weather summary for Arlington from April 1 to June 26, 2010

Figure 2 shows the weather data for UW-Agricultural Research Station at Marshfield.
Precipitation was tracking at a pace slower than the 30-yr normal, but it has since
caught up. Growing degree unit (GDU) accumulation since January 1 is ahead of the
30-yr normal. But, while total GDU accumulation is ahead of schedule, the GDU accumulation
for various planting dates is equivalent to the 30-yr normal for every planting
date, except for a May 15 planting date. For a May 1 planting date, GDU accumulation
was slower than the 30-yr normal while the crop was emerging, but accumulation has
since caught up.

Figure 2. Weather summary for Marshfield from April 1 to June 26, 2010

Figure 3. shows the GDU and precipitation deviation of 2010 (April 1 to June 26)
from the 30-yr normal. Precipitation accumulation is similar to the 30-yr normal
for both Arlington and Marshfield. At both Arlington and Marshfield, GDU accumulation
is higher than the 30-yr normal, but less than the four years that were greater
than one standard deviation from the 30-yr normal. At Arlington, the production
years of 1985, 1987, 1988, and 1991 were warmer than 2010. At Marshfield, the production
years of 1987, 1988, 1991, and 1994, were warmer than 2010.

Figure 3. Growing degree unit and precipitation deviation of 2010 (April 1 to June
26) from the 30-yr normal. Other included years were selected using
+ one standard deviation from the 30-yr normal.

The crop is off to a good start. This is a year that reminds us of what early planting
and ideal field conditions during planting can do for corn growth and development.
For the most part, weather has been as ideal as it can be, but a lot of growing
season is left.